The aim of this study is to determine the maximum tolerable dose of radiation that can be delivered to treat localized tumors in combination with continuous infusion hepatic arterial floxuridine (FUdR) (0.2 mg/kg/day) for patients with localized intrahepatic malignancies. We hypothesize, based on our previous experience with > 100 patients treated in a similar fashion, that the tolerance of the liver to partial radiation will be described by an NTCP model that we have partially characterized. Furthermore, we hypothesize that by determining the parameters of this NTCP model, we will be able to safely administer higher doses of radiation to patients with intrahepatic cancers than have been possible to deliver in the past.